Marshall Stanmore Repair

[Hkekkonen]

My Stanmore is powerless again. Have found some major issues in it. Will share the info later.


Came across with this post on another forum. (mikrocontroller.net/topic/547728)

Translated it from Germany to English.

From Josef Aichhorn (Guest), first contact with my inquiry: 16.12.2022 01:00

Hello everyone!
I want to thank everyone who helped me repair my MARSHALL STANMORE! Yes, it's working again - something I hardly believed after initial research.
The link to Badcaps by "4:46 (Guest)" was very efficient! THANK YOU! Among tons of photos and posts, I found the values and designations of the burned components!
In short, facts (values and designations of the components, see schematic sketch):

2 defective electrolytic capacitors (EKLOs): C59 [electrolyte leakage], C80 [bulging cap], [both 470µ/50V], and as a precaution, 4 more of the same type replaced.
Defective parts: Si 1.6AT, Q7, C124, U1, R18+R104, R19,
Defect due to the removal of the black, hard, tough paste: R69 (not in the power supply: R41[3R30]).
A heartfelt THANK YOU to everyone!
Josef from Austria
PS: As a small thank you, I want to share my painstakingly created sketch of the switching power supply (from Marshall Stanmore) here - because I can imagine that it might be useful ;-) !
Maybe someone can send it to the Badcaps forums - I don't have authorized access yet... just for viewing. °[:->)

And here is the sketch:

[jingleslacks]

Hi Friends,

I'm not too bright, and I could use some guidance. I don't know a lot of part names or terminology, but I'm trying to follow along. I was measuring voltage across my chips, and my cat got curious and a bit too close to the exposed electronics. I turned my head for a second to shoo him away. In that moment, I was met with a tiny pop, flame and smoke from my leads shorting something. I'm pretty sure I fried the chip. I don't know it's sole purpose, but now I'm not getting any real measurable voltage to that board. My (what I think is my BIOS chip) was getting 1.8V- now nothing. I don't remember the voltage of the cooked chip. Any wisdom would be appreciated. If anyone has the file for that chip, it would be double appreciated.

[jingleslacks]

I realised that I just posted my previous in the wrong forum since I have a Stanmore II. In other news, I found these in another group. Hope they help

[Dioniso]

Hello everyone, I had an update issue installing the last firmware version on my Stanmore II. Actually I'm able to power on the speaker but control panel seems freeze.
It is also possible to soft reset the speaker and to connect the smartphone to the device but after few seconds panel get freeze again.
s anyone aware how to hard reset the software? I saw that we have a service port on the back, it is usefull for the scope?