Marshall Stanmore Repair

[dannybloe]

Re: Marshall Stanmore Repair

Intersting follow up: after placing the bluetooth module back in the Stanmore, all seems to work again. Guess the module had to get a proper connect somehow.

[dannybloe]

Re: Marshall Stanmore Repair

Can somebody tell me what the value is of L13? Turns out while assembling everything together, this one was broken (no burn marks). Can't exactly tell what the colours have been. Looks like it is similar to L7 next to it but I'm not sure.
Is this an inductor?

[jonathandean]

Re: Marshall Stanmore Repair

Hi,

Interesting thread. I have replaced the burned R23 (220 ohm) with a bigger resistor underneath the PCB. I have attached a picture so you can see how I have done it.

I have also a picture for you who have problems finding the 3.3 uF capacitor.

PS still broken but faultfinding is still in progress.

Hi My 3.3 uF Cap seems to be reading short, it looks like this goes to a winding on the transformer,could this be the problem? Has anybody changed the transformer on their stanmore?

[kros]

Re: Marshall Stanmore Repair

Hi
If someone needs a New working board Marshall Stanmore Main PCB, it can be bought at this link:

https://reverb.com/item/48237590-mar...e-main-pcb-cpi

I bought the last one and everything works, the board is completely new

If someone needs it too, Marshall Stanmore Front Panel with PCB (cpi)
https://reverb.com/item/48234877-mar...l-with-pcb-cpi

Thanks

[SkyHeart]

Re: Marshall Stanmore Repair

Hey Guys,

has any one found any diagram or schematics for this PCB?
I have 2 of this Stanmore on my table with the same issue, both light up and everything work except from no sound output.

the area around OB2269 looks a bit hot but I wasn't able to find the OB2269 in our local stores, couldn't find it on digi-key as well, any help or more information is appreciated.

[kros]

Re: Marshall Stanmore Repair

Hey Guys,

has any one found any diagram or schematics for this PCB?
I have 2 of this Stanmore on my table with the same issue, both light up and everything work except from no sound output.

the area around OB2269 looks a bit hot but I wasn't able to find the OB2269 in our local stores, couldn't find it on digi-key as well, any help or more information is appreciated.

Hi
I don't know where you are looking for this chip ,but there is a lot of it on ebay in europe

https://www.ebay.de/itm/223882780254...kAAOSw-xJisx1S
https://www.ebay.de/itm/133518480526...gAAOSw7dth4q19
https://www.ebay.de/itm/361705477744...QAAOSwCehi36eR

[SkyHeart]

Re: Marshall Stanmore Repair

Hi
I don't know where you are looking for this chip ,but there is a lot of it on ebay in europe

https://www.ebay.de/itm/223882780254...kAAOSw-xJisx1S
https://www.ebay.de/itm/133518480526...gAAOSw7dth4q19
https://www.ebay.de/itm/361705477744...QAAOSwCehi36eR

Thank You @kros, yes I found it on ebay after posting and I did order it, though i'm not sure if the cause of the issue is from that IC but it's good to have it just in case

Thanks again.

[kros]

Re: Marshall Stanmore Repair

Thank You @kros, yes I found it on ebay after posting and I did order it, though i'm not sure if the cause of the issue is from that IC but it's good to have it just in case

Thanks again.

For me, the best option was to buy a new motherboard, in mine there was a burned hole in the laminate where the TAS5342A chip is, it was completely burnt. Earlier I wrote to marshall asking for a new motherboard, they said they can't sell me, but they can fix it, it will be around 200 euros plush shipping costs

That's why I was able to buy a new motherboard for half the price that Marshall was offering

[SkyHeart]

Re: Marshall Stanmore Repair

Update:
The power amplifier was fried and the 7812 IC together withthe shorted D7 located underneath. Everything replaced except the amplifier.

The unit started up and this time the bluetooth worked as well Could easy pair it so there is hope for the unit but we see when I receive the power amplifier.

The amplifier IC has the marking 42TTI A87CG4 (?) but someone else suggests that it could be a TAS5342A IC?

Has anyone information what the amplifier IC could be?

Hey @Chris_J
were you able to fix your issue?
I also replaced 7812 IC and the D7 including the TAS5342A IC, R23 and 3.3 cap but still no sound, I can pair with bluetooth and everything seems to work but still no sound coming.

[kros]

Re: Marshall Stanmore Repair

Hey @Chris_J
were you able to fix your issue?
I also replaced 7812 IC and the D7 including the TAS5342A IC, R23 and 3.3 cap but still no sound, I can pair with bluetooth and everything seems to work but still no sound coming.

Hi.
My friend bought this IC from two different sellers they were new, At the first seller after replacing this IC there was no sound , bought 2 pcs and none of them worked, when he bought from another seller another two IC the IC was working properly, my friend said that there are a lot of fakes of this IC . And you have to be careful when buying.

[SkyHeart]

Re: Marshall Stanmore Repair

Hi.
My friend bought this IC from two different sellers they were new, At the first seller after replacing this IC there was no sound , bought 2 pcs and none of them worked, when he bought from another seller another two IC the IC was working properly, my friend said that there are a lot of fakes of this IC . And you have to be careful when buying.

Thank you kros for the information,

I got the amplifier IC's from mouser.com which is a very known website for selling electronic parts so I don't think they are fake.

[SkyHeart]

Re: Marshall Stanmore Repair

Hi Folks,
I was finally able to find the issue with my Stanmore, after changing the 12v regulator which is in the middle of the PCB (KIA 7812A) i found out that it's not getting any input current, had to remove it again to trace the input which is feed by L7 it looks like a normal resistor it was a bit toasty, I'm not sure why the numbering on the PCB says L7.
my issue is number 2 from the first post, everything works without sounds output.

I changed that L7 with a normal 47ohm resistor and I got sound.

attaching a picture of L7 location.

[SkyHeart]

Re: Marshall Stanmore Repair

I think it's an Inductor not a resistor, for me it's the first time I see an Inductor in the shape of a resistor
it's been a while since last time I worked with Electronic it's been more than 15 years.

thanks for the help guys.

[SkyHeart]

Re: Marshall Stanmore Repair

Hello Guys,

it's me again trying to fix this Stanmore speaker mess, after changing a lot of components I was able to fix the power issues, the speaker comes on, lights are on, Bluetooth connects fine, when I play music sound comes for few seconds then I will hear 2 or 3 loud static from the speaker and sound disappears.

if anyone had a similar issue and was able to fix it please do share the information, I did change the TAS5342A IC.

[DeeJayAlex]

Re: Marshall Stanmore Repair

Hello guys,
R96 is burn can you help me with its value?Thx

[SkyHeart]

Re: Marshall Stanmore Repair

Hello guys,
R96 is burn can you help me with its value?Thx

can you post a picture of the location?

[StephE]

Re: Marshall Stanmore Repair

Hello,

did you ever figure out the values/types of the three diodes ?

I have the same problem.
And lots of leaking caps.

Regards

[StephE]

Re: Marshall Stanmore Repair

Hello guys,
R96 is burn can you help me with its value?Thx

Hello,
on mine R96 is 10kOhm, (labeled "01C")

Do you know / could you check the values of ZD1 and ZD3 please if it is still open ?

Regards

[DeeJayAlex]

Re: Marshall Stanmore Repair

can you post a picture of the location?

The Location of R96

Thx.

[DeeJayAlex]

Re: Marshall Stanmore Repair

Hello,
on mine R96 is 10kOhm, (labeled "01C")

Do you know / could you check the values of ZD1 and ZD3 please if it is still open ?

Regards

Thank You for reply!
ZD1 and ZD3 seem to be ok(0,7mV on diode check)
they are zener diodes, which unfortunately I don't know what value they are
Soon I will start to repair it and if it is successful I will check the voltage drop of the zener diodes so that we can figure it out and I will let you know.
Regards.