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820-00840 not powering on

M

myiannakou

Member
Was power cycling but after reflowing CD32's power cycling has stopped
Amp meter shows 5.19v 0.02a
Has had liquid damage in the past as white markers are red.
No signs of corrosion

PPBUS_G3H = 0.09v
PPDCIN_G3H = 5.20v

PPBUS_G3H resistance to ground = 14.52MOhms

I'm thing to replace the CD32's ???

Thanks in advance
 
2informaticos

2informaticos

Administrator
Staff member
"PPBUS_G3H resistance to ground = 14.52MOhms"
High value ohm readings don't help.
We need to know more about the power rail, apart of no short.
Use diode mode; only switch to ohm scale for very low values.

Do you get 3V3_G3H?
 
M

myiannakou

Member
I went ahead a replaced both CD32's but problem still persists

3V3_G3H = 3.4v
PPBUS_G3H = 0.28v
PPDCIN_G3H = 5.20v

PPBUS_G3H = 0.428v diode mode
 
M

myiannakou

Member
PPBUS_G3H voltage with battery connected = 0.97v

Noticed that PPDCIN_G3H_CHGR_R = 5.20v but PPVIN_G3H_P3V3G3H = 4.88v . Does that sound correct to you???
 
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M

myiannakou

Member
With F7000 removed voltage at C7050 = 0v

Bare in mind I only have charger plugged in and not battery

Could it be a bad U2890 Rom chip? Does the ROM chip U2890 W25Q80DVUXIE have to come from a donor or can it be purchased from places like mouser?
 
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2informaticos

2informaticos

Administrator
Staff member
U2890 has the frimware required for CD3215 chips and U2800.
Must come from donor board, or new one flashed with correct file.
 
M

myiannakou

Member
I found a replacement U2890 but it made no difference and besides, I think if it was the ROM I would have power cycling right?
Do you think it could be the HAL sensor or am I just unlucky and the two CD32's I bought new off ebay are crap??
 
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2informaticos

2informaticos

Administrator
Staff member
Should have a problem into U7000 area, as no voltage with battery too.
Post basic U7000 voltages; P_IN, AUX_DET, VDDA/P, SMC_RST*, AUX_OK, A/BMON.
 
M

myiannakou

Member
Are these the readings you asked for? I wasn't to sure. These are without battery.

DP_INT_HPD - 0v
TBA_AUX_DET - 1.29v
TBA_VDDA - 5.13v
TBA_VDDP - 5.13v
SMC_RST_IN - 0v
SMC_RST_BTN_L - 0v
SMC_RST_BTN_R_L - 0v
SMC_AUX_OK - 2.32v
CHGR_AMON - 0v
CHGR_BMON - 0v
 
2informaticos

2informaticos

Administrator
Staff member
"SMC_RST_IN - 0v"
I didn't ask for that one; please read correctly.
I used U7000 internal notations; check the corresponding external ones.

SMC_RESET_L gets steady 3V?
 
M

myiannakou

Member
P_IN (PPDCIN_G3H) - 5.20v
AUX_DET (TBA_AUX_DET) - 1.29v ,
VDDA (TBA_VDDA) - 5.13v
VDDP (TBA_VDDP) - 5.13v
SMC_RST* (SMC_RESET_R_L) - 0v
AUX_OK (SMC_AUX_OK) - 2.32v
AMON (CHGR_AMON) - 0v
BMON (CHGR_BMON) - 0v

SMC_RESET_L - 0v
 
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