iriver H120 will not switch on

[klawit]

Hi there,

I got hold of my old iHP120 again. It is rockboxed has the RTC and CF mod and was workinmg fine when I used it years ago. Unfortunately it is no longer showing any sign of life except the charger LED is coming on when the charger is attached. At first I thought the battery is dead due to lying around without being recharged regularily, but the iriver is able to charges the batterie up to 3.9V. So the system should have enough power to do anything. But as I said no sign of life. After checking the PCB I realized chip U28 marked TXQ being quite hot. No idea what this chip is used for. I found another post where this chip is identified as TL3045 but this tells me little. Any information on that and how I should proceed?


UPDATE

Further research indicates U28 is a LTC3405 DC/DC converter. I think it should supply the ColdFire 1.8V core voltage. I verified the parts voltages. Pin 1 reads 0V which should disable DC/DC operation at all. Unfortunately I measured 3.6V at pin 3 which is way to much for the ColdFire CPU. Is the CPU able to survive? The part seems to be broken, does it make sense trying to replace?

[JaroMi]

Hello
Check voltage on coil above U28 and on C 98 (under mark R108) - if I remember correctly- this is Vcc for Coldfire.
I repaired broken iHPs with even 4v5 on this Capacitor :-) BUT - if processor is hot, really hot this operation is helpless... I mean - I think, Coldfire can believe 5V on a short time on Vcc, but quickly get thermal death.
Remove U28, get 1,6-1,8 V on  C98 so try to start machine.
LTC was free to sample from Linear, but now - I don't know.
Ant -I think Texas's Li Ion charger need repair too.
I'm sorry , my English is so... cheap
:-)
Nokia's 8,4V charger victim?

Good luck
J

[klawit]

Hi J,

I wasn’t sure but the CPU seems to be a quite robust one. I removed the dead LTC and applied 1.5V from a AA battery. Astonishingly the LCD immediately switched on and the Iriver OS booted up. Next step is to order a new LTC and try to solder it in. There was a message “check HDD connection”.  So maybe there is something broken or voltage was too low. Nothing from Rockbox which should be on the CF card but I’ll see when the new LTC 3405 is in. You used the normal version not the one with fixed output at 1.8V, right?

Thank you for your reply. I think I wouldn’t have tried anything without.

I haven’t used a Nokia charger but mine is providing too low a voltage and needs to be replaced. I’ve read about the USB mod, maybe an option. The TI is fine, the battery is fully charged by now. Core voltage was at 3.6V or higher over the night until I recognized something was wrong and disconnected the battery. Great protection circuit Motorola added to the design. LTC replacement was ordered yesterday. I hope I’ll manage soldering well.

Thanks again.

Greetings
klawit

[JaroMi]

Great news Lucky one  !

LTXQ - Yes, 1,8V fixed.
HDD conn - check please voltage powering hdd 3V3 from LTC3440 (LNTP) avaiable on L9 and C94 on the proc's left side. Chip is near 11xxxMHz quartz. It's maximum is 6V and I think, it's OK, but... Or connection inter-board.

Jaromir

[klawit]

Jaromir,

Are you sure it is the fixed version? I believe it’s the one where you set the output voltage by a couple of resistors, isn’t it? The marking TXQ or LTXQ is giving a hint to this. Unfortunately I’ve no time to continue working on the iRiver. Possibly next week or so.

Greetings
Klawit

[JaroMi]

right:) resistors... Fixed LTZP LTZQ. my bad.

Regards
Jaro