Electronics Help Needed

[Turbo]

This is a continuation of this thread.
https://www.mig-welding.co.uk/forum/threads/yettie-radio.128168/#post-2238981

The lcd display on my van failed & I bought a replacement from Aliexpress, installed it in the van & I had a fully functioning display again for 10 minutes, then pixels started disappearing before the screen went blank apart from the backlight. After a few more minutes the unit died completely.

Got a full refund from Aliexpress so I opened up the new (broken) unit.

All looked ok apart from 4 surface mount capacitors, 2x220uf & 2x470uf. They have some sort of glue around them & some of it looks burnt. Could this be a sign of failed capacitors? Would this cause the type of failure the screen suffered?

What I was really hoping to do was to fit the lcd of the new unit into the vans original unit.

But there's a problem, the original screen's ribbon cable (top) was joined directly to the pcb & has 50 connections.
The new screens cable (bottom) plugs into a socket that's soldered to the pcb but it only has 30 connections!

Is there any way that these screens can be swapped?

If not I might have a go at repairing the new screen, I have some suitable capacitors that I can swap for the dodgy looking ones.

 

[sako243]

Those electrolytics normally swell when they fail. The burning could be a sign of failure but I feel its likely to have been caused by something else.

Still they're only a few pence so you don't have much to lose by changing them out.

Is there any way that these screens can be swapped?

Not trivially.

 

[Alan Reynolds]

It looks like the glue they use to hold the capacitors in place before flow soldering. The rubber in the end of the capacitors can cause discolouring.
Maybe try and get an original from a vehicle dismantlers.
It’s a shame that vehicles have become so complicated as there will be many vintage and veteran vehicle in the future that will not be able to be used due to obsolete electronics.

 

[mtt.tr]

When you shine a light through the display is there any digits?

My vivaro was backlit using bulbs, these had blown

 

[mart]

This is a continuation of this thread.
https://www.mig-welding.co.uk/forum/threads/yettie-radio.128168/#post-2238981

The lcd display on my van failed & I bought a replacement from Aliexpress, installed it in the van & I had a fully functioning display again for 10 minutes, then pixels started disappearing before the screen went blank apart from the backlight. After a few more minutes the unit died completely.

View attachment 394129

Got a full refund from Aliexpress so I opened up the new (broken) unit.

View attachment 394127

All looked ok apart from 4 surface mount capacitors, 2x220uf & 2x470uf. They have some sort of glue around them & some of it looks burnt. Could this be a sign of failed capacitors? Would this cause the type of failure the screen suffered?

What I was really hoping to do was to fit the lcd of the new unit into the vans original unit.

View attachment 394128

But there's a problem, the original screen's ribbon cable (top) was joined directly to the pcb & has 50 connections.
The new screens cable (bottom) plugs into a socket that's soldered to the pcb but it only has 30 connections!

Is there any way that these screens can be swapped?

If not I might have a go at repairing the new screen, I have some suitable capacitors that I can swap for the dodgy looking ones.

This is my 'go to ' site for electronics info.

Electronics Forum (Circuits, Projects and Microcontrollers)

An electronics forum to talk all about circuits and projects.

www.electro-tech-online.com

 

[Turbo]

Thanks for the replies.

When you shine a light through the display is there any digits?

My vivaro was backlit using bulbs, these had blown

The other side of the pcb has smd leds to backlight the display. I'll try it in the van with a torch behind it.

Maybe try and get an original from a vehicle dismantlers.

They're a common fault across all PSA group vehicles, so used ones are not cheap. You also have the issue that there are at least 7 different screen types depending on vehicle & spec.

I'll have a go at fixing this 'new' one, nothing to lose. If I'm not successful I'll try another one from Aliexpress.

If it fails too there's a company in Italy doing a kit to fit a new screen to your original unit but it requires some delicate soldering.

 

[Turbo]

Am I correct in thinking that the dark strip on the end of a smd cap denotes the negative leg?

 

[sako243]

Am I correct in thinking that the dark strip on the end of a smd cap denotes the negative leg?

Yes

Those caps are likely part of the power supply. There's a small (but unlikely) chance the ESR of the cap might matter. If you can figure out the manufacturer code then you can possibly find the spec on it.

It's unlikely to make a difference in this instance, I'm just saying it can make a difference.

 

[Turbo]

Yes

Those caps are likely part of the power supply. There's a small (but unlikely) chance the ESR of the cap might matter. If you can figure out the manufacturer code then you can possibly find the spec on it.

It's unlikely to make a difference in this instance, I'm just saying it can make a difference.

I've just repaired a couple of Humax pvr's that were fitted with poor quality 'Sam Yung' capacitors. The ESR in them goes miles out of tolerance & they cause issues with the power feed to the hdd, eventually bricking the drive. I had to replace one drive but I think I got the other one fixed in time.

 

[Turbo]

As an update to this - I chickened out & took a chance on another Aliexpress unit, from a different seller.

The new unit arrived in a couple of weeks, installed it in the van & it has worked perfectly since. The bluetooth is also working on this one - it didn't work on neither my original nor the first new unit. I can now connect my phone via bluetooth & use the van's hands free calling. It also displays the music on the phone & I can play it through the head unit.

As a test I put some music on a 1 tb ssd drive & hooked it up to the van's usb socket. The drive's music content came up on the screen & I can use it like an mp3 player. The drive can hold up to 250,000 songs so plenty of room to hold my music collection plus make some playlist folders.

There are a lot of other functions now available to me with a working display screen that I didn't know about. Wish I'd fixed it ages ago instead of waiting 2.5 years!