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Sunday
Mar172019

PURE Avanti Flow – replacing the OLED display

An Avanti Flow with new OLED displayI’ve had a few requests asking for advice on replacing the OLED displays in a PURE Avanti Flow. Since I had a spare (white) OLED display that also fits my portable PURE Evoke Flow, eventually I sourced a used, working  Avanti Flow which needed a new display. It’s a very common problem: the working life of these OLED displays is about 30,000 hours so they just wear out over time.

As I expected, the Avanti Flow is much trickier to repair as it contains a sandwich deck of printed circuit boards inside, each connected by a spaghetti of ribbon cables all located in a restricted space. I needed a number of electronics tools to reach around and manipulate cables and connectors, and the work was more like keyhole surgery at times!

My advice is that if you don’t have the experience of handling confined and delicate electronics like this, the scope for overlooking something, not connecting something properly or damaging the radio’s hardware is quite high and it’s likely that you would spend hours struggling only to be unsuccessful and disappointed by your efforts. Again, the Avanti Flow is quite a lot more intricate to repair than an Evoke Flow so I’d think hard before deciding whether to throw time and money at replacing the OLED display on a DIY basis and risk disappointment.

Despite everything I was pleasantly surprised that I managed to get mine working first time and it now sports a new white OLED display.  What follows is a general guide only to give you an idea of what's involved. I have tried to cover everything but I don’t guarantee I covered every last little thing, nor in exactly the right order, and I’m not responsible for anything that’s been left out. Hopefully without explaining the ‘baby steps’ my photos and text will show a skilled tech. an idea of what’s involved so you can decide whether to tackle this job yourself. As far as I know there is no such guide about the Avanti Flow anywhere else online.

You will need to set aside some quality time (2 hours), or maybe split the work in two phases, working carefully and delicately, while being vigilant and observing the routes of all ribbon cables and cable headers closely to ensure you can disconnect and reconnect everything properly.  It’s hard to replicate a multi-million dollar factory at home but a number of tools like long-reach Philips screwdrivers, hooked probes, gripping tools, long nose ‘radio’ pliers, bent-nose ones and more will be needed  and you’ll also need to be patient and pretty resourceful to complete the repair successfully. It's tricky, but having said all that, it can still be done successfully!

Opening up an Avanti Flow

I am guessing that the radio internals are pre-assembled on the factory bench before being fitted into the cabinets. I could not figure out how to access the display from the front. The front panel and speaker grille were very secure with invisible fixings at each corner, so not wishing to damage it it’s necessary to start from the radio’s rear panel instead. As it turns out, that’s likely the correct thing to do, partly because of some ribbon cables that connect to the display board deep from inside the radio. If anyone knows differently, let me know!

Remove 8 x Phillips screws [click to see]The rear panel removes easily and can hang out [click to see]With the radio face-down on a cloth, start by removing 8 x Philips screws from the rear panel.  The rear will then lift out completely and can be swung to hang over the edge. It also carries the power supply and bass port tube.

Rear panel hanging down before removing the sub woofer [click to see]Reach inside the radio and use radio pliers to unhook the 2 x leads from the sub-woofer speaker. Remove the acoustic wadding.

Sub woofer terminals can be removed next [click to see]Internal view after removing acoustic wadding [click to see]

Remove the sub woofer

The speaker mesh can be prised out carefully [click to see]... revealing the sub woofer [click to see]Underneath the radio, the speaker mesh is a simple interference push-fit and can easily be teased out with eg a pointed probe. Then remove 4 x Philips screws (15mm long) on the speaker plastic mounting ring, and then unscrew the sub-woofer (4 x 10mm screws) and extract the speaker from inside the radio. This makes the interior accessible.

Then the sub woofer can be withdrawnReach through the speaker cut-out and unscrew 2 x nylon P-clips that secure wiring looms to the cabinet; some black foam rubber ‘shims’ were removed from ribbon cables next.

First glimpse of the radio board, the first PCB to be removed [click to see]The Avanti Flow carries a stack of circuit boards inside the cabinet: first is the radio board, underneath that is the audio board and finally the display/ front panel switch board is fixed right at the bottom. They are all interconnected with various ribbons and wire connectors and they all mount on plastic pillars using self-tap screws.

Radio board

Radio board with copper-screen ribbons x 2, and ipod dock above (and more ribbons!) [click to see]The radio board is held with 4 x 8mm long self tap screws, one screw also traps a (solder tagged) shielding wire hooking to the PSU screen. I used a long-reach electric screwdriver with a (magnetic) Philips tip to remove the screws successfully. You don't want to be dropping them inside the radio.

Unhook 2 x ribbon cables on the ipod dock. They will simply pull out and they connect to the main board.

Remove the ipod dock ribbons and pin header [click to see]The radio’s two main wire looms are an obstacle: stiff and inflexible, they obstruct the removal of the boards, but you can cut off any nylon tie-wraps to loosen up the wiring. I cut off all the tie-wraps.

Gently lift the radio board away a little, I moved it to one side. Two ribbon cables (10mm and 15mm wide) are shielded with copper tape; these go to the OLED display board at the very bottom of the radio, so unpick the copper foil and unhook both ribbon cables. (That’s because later I saw it’s easier to unhook these two ribbons from the 'radio board end' and leave them connected to the display board.  Otherwise you will need eg a long-reach flat-bladed tweezer to reconnect them to the display board (which luckily I had!) once in situ. My photos however show these two ribbons as disconnected from the display, not the radio board.

The radio board partly removed. See text re. the two ribbon cables [click to see]

Audio board

The audio board is revealed [click to see]

Disconnect 2 x header wires on the radio board and lift it away to reveal the audio board under it.  Note how a short 20mm ribbon is fitted between the radio board (underside) and audio board (top side).

The audio board lifted slightly, note the headers underneath [click to see]The audio board is held down by 4 x black self tap screws.  Disconnect 2 small pin headers along one side (3-pin and 4-pin – see how a very short wire disappears inside into a front stereo speaker), and then disconnect a 3-pin and 5-pin on the board’s longer edge.

Reach through the speaker cutout and unhook the headers - I marked them with Sharpies to colour-code them [click to see]

Disconnecting the audio board [click to see]This leaves three 3-pin headers on the other short side of the board. I used coloured Sharpie pens to mark which cable plug goes into which header. See again how a very short cable disappears into the cabinet to the other front stereo speaker. The other two cables carry ferrite cores which are a nuisance, but they  slide back up the cables out of the way. Having colour-coded the wires, unhook them from the audio board and gently remove it or set it to one side.

3 x pin headers (inc. one stereo speaker), mark them and remove [click to see]Audio board removed [click to see]The display board revealed [click to see]The OLED display/ switch panel removed [click to see]

Display board

With the audio board removed, the OLED display/ switch is revealed. It has 6 x self tap screws and another 10mm ribbon cable.  Taking this apart, the OLED itself can be lifted off, helped by e.g. a right-angled probe.

Separating the display [click to see]The OLED display ribbon clearly shows pins 1 and 22 and the ribbon cable can be disconnected from the PCB header by gently sliding out the ribbon connector’s black plastic holding clamp. (See my Evoke Flow guidance and photos for more details – it’s the same connector).

Preparing to disconnect the old display [click to see]The flat ribbon latch (black plastic) is very delicate [click to see]Disconnected, note the pin labels 1 - 22Remove any protective poly film off the new OLED display and clean the front display window. The new display ribbon is passed through the mounting frame the same as before. My (white) display was a direct replacement, the same shape and ribbon orientation. Unfortunately it would be easy enough to get a new display upside down or the wrong way round and you would never know until the radio was assembled again, so take some photos if necessary to remind you of the display’s orientation. I also used two small dabs of glue to hold the new OLED on its black plastic mounting frame. Unlike the PURE Evoke Flow, everything is located securely in place with no scope for misalignment.

The PCB also carries the front panel push switches and an LDR (light-dependent resistor) which must all align properly with the front fascia and its buttons.

Reassembly

With the new OLED fitted and the display board screwed back in place, the audio board can now be reconnected which is easier said than done. There are no less than seven PCB headers to reconnect and it’s also easy to get the board the wrong way round in situ.

Re-installing the audio board and its wiringI'd left my radio board hanging around, partly connected. See text about those two copper-clad ribbons [click to see]Don’t overlook those two (15mm and 10mm) ribbons that stem from the display board and go ‘past’ the audio board to the radio board above it. Of course, ensure all ribbon cable conductors mate with the corresponding PCB header properly: the metallic conductors can be seen and they must mate together when the ribbon is inserted into the connector.

I used flat-bladed radio tweezers (similar to ‘postage stamp’ tweezers) to grip and slide the ribbon cables back into their headers successfully. This worked extremely well.

The audio and radio boards back in situ [click to see]Probably the hardest part was re-connecting the audio board leads, which I found very fiddly and time-consuming. I used a variety of long-nose pliers, bent-nose pliers, hooked probes and a lot of dexterity to hook them back UNDERNEATH the audio board (which lies component-side down), but it was possible with care and a lot of keyhole surgery. Definitely not a job if you have ‘sausage fingers’ but it can be done.  Slide those ferrite cores back up the wires out the way, if necessary.

This short 20mm wide ribbon connects the audio and radio boards [click to see]

Re-locate the radio board in place, reconnecting a short 20mm wide ribbon on its underside to the audio board located underneath. The ipod dock ribbons can also be reconnected.

The ‘memory’ of various wire cables helped with routing them to the relevant headers on the radio board and it was fairly straightforward to re-connect everything else. Soon I was only left with the sub-woofer cables to hook up, so the speaker and grille were refitted and the sub-woofer was finally reconnected.

I decided to leave off all P-clips and nylon tie-wraps, leaving the wires routed loosely inside. The acoustic wadding was put in again and the case rear was closed up with 8 x screws.

I did notice white specks of dirt etc inside the display window (not on the new OLED), which is a shame but I decided to leave it alone as it’s an old radio anyway and I just wanted to prove a point. Power up time... would it work?

Powering up again

Every electronics hobbyist knows the feeling of anticipation when powering up their project for the first time. Switching on at the mains and after a few seconds I was rewarded with the Avanti Flow splash screen (in white) followed by Initialising......  and then the radio burst into life. I’m thrilled to say the repair was entirely successful, and the radio could be retuned to local DAB stations without a problem. All buttons and menus worked as expected.

After a few seconds, the splash screen appeared [click to see]Tuning in... [click to see]

More stations... [click to see]Standby screen [click to see]

Replacement OLED displays are getting harder to source, but those purchased via Alibaba seem to be the best quality. I can only re-iterate that the Avanti Flow is a very fiddly job best undertaken by those who are used to fiddling with electronics and manipulating wires and PCBs. With the right skills, patience and tools it’s entirely possible to fit a new display to an Avanti Flow as I hope the above photos prove.

Reader Comments (2)

This is fantastic, thank you so much. Think it will take me more than 2 hours.
Kind Regards
Bob

April 2, 2019 at 12:46 | Unregistered CommenterBob

Thanks Bob, good luck and let us know how you get on (and what display you used)

Alan W

April 3, 2019 at 16:20 | Registered CommenterAlan W

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