Lidt search på Marshall 203-JN3018 eller efter Marshall Stanmore fortæller at det er kendt at de går i stykker.
Her er en der bare bruger den til noget andet https://www.youtube.com/watch?v=0EqzEmTbGVQ
Her er der en som bygger en anden forstærker ind i kabinettet og genbruger enhedernehttps://techfindings.one/archives/3375
En som heller ikke virker https://www.youtube.com/watch?v=4aJSuT7_y3A
Her står der i kommentarerne:
3 years ago
I've been troubleshooting a dead Stanmore today, and it seems like the voltage to the MCU is to low. I get 0.7 volt, the MCU requires something like 3.5 - 5.5. There is a MC34063A used to step down from 15 volts, but I only get 0.7 volts on the output. Can't see any burnt components so I'll try to replace the MC34063. I had to order it so it will probably be in a few weeks. If someone wants to measure this voltage on your Stanmore, please note that the circuit board contains high voltage so make sure you know what you are doing. Don't blame me if you mess up. Also note that any warranty will be void if you take if apart. The voltage can be measured on the 4-pin SIL header located in a cutout in the board named "stanmore shield". The two pins closest to the bluetooth-board is voltage and ground. I guess a working Stanmore would have something like +5 volt, instead of 0.7 volts. I applied 5 volts from an external source to these two pins and the LED:s, buttons and bluetooth works just fine then. I had the Stanmore's power cable disconnected while doing this, i.e only the MCU and bluetooth where powered. I am pretty sure that the power to the amplifier is OK and I didn't want to stretch my luck. I'll let you know what I find :-)
2 years ago
Hey Dahook, I managed to test what you describe in first comment, I find out the SIL header you mention on the board name stanmore shield, and it gives me a random measure between 2.4 and 1.5 I don't have nothing to power up the circuit so I did it with the unit connected, I guess the voltage is not as low as your, but I'm collecting information to get it to a person with some more experience than me.
Thanks for your help
Måske du kan lokaliser de regulatorer de snakker om og se om der er input spænding
Her er data på MC34063https://www.onsemi.com/pub/Collateral/MC34063A-D.PDF