ET5000 will not power up at all. No led

[crowhater]

Have 2 units that suddenly just stopped working. Started with randomly not powering up. Turned it off and then on again and then it started...but more and more often it hanged and did not power up after shutting it down. and now it does not power up at all. The power supply is ok but the unit will not start. Have not changed any images or booloaders, just used it.

Anybody with this failure? Schematics over the hardware or service manual would be really nice if it is available.

Don´t want to start HW troubleshooting before asking here and receiving any documentation. Think more people have the same issues that the HW just stops working without any reason.

Thanks in advance...

[crowhater]

Have 2 units that suddenly just stopped working. Started with randomly not powering up. Turned it off and then on again and then it started...but more and more often it hanged and did not power up after shutting it down. and now it does not power up at all. The power supply is ok but the unit will not start. Have not changed any images or booloaders, just used it.

Anybody with this failure? Schematics over the hardware or service manual would be really nice if it is available.

Don´t want to start HW troubleshooting before asking here and receiving any documentation. Think more people have the same issues that the HW just stops working without any reason.

Thanks in advance...

I will help you CrowHater...

Before it stopped working at all it sometimes fired up....after couple of tries. Thought that it could be some heating problem.
My first test was to put some heat on the circuitboard. Tried on several places and whenever it was hot enough it fired up. as soon it was cold it did not work. thought it was the processor first....did a resoldering job...did not work. Tried to resolder the memory...no success. Tried then to heat each component separately. took some time. Managed to narrow down the area a lot. Ended with one component. Hidden under the other circuitboard (card reader).
Tried to put the soldering iron directly on the component and every time it was done it booted correctly. YEAAAA.....bingo...

had a spare part of that step down converter. This converter decreases the voltage from 12V to 1.2V, which powers the processor...

Removed the old one and put in the new one. And Voila...it reboots now every time.

Same problem with both units....

See attached picture, have marked the location. The chip is U4 and model is. LSP5503

https://pdf-datasheet-datasheet.netd...iconductor.pdf


Hope it helped CrowHater.

Thanks...it did ... ;-)

TIP: each converter has a coil attached on the switching pin(output). Just test on the coils the voltage on each coil. Should be 10V, 5, 3,3 1,8 and 1.2 V.
There are 6 coils on the circuitboard. If all the outputs are working...then it is something else than the powersupply.....in my case it was the powersupply of 1.2V that did not work all the time, only when warm it started to work....