[power supply vs screws heads up.]

Hey guys, this week I've had two xboxs that were untouched seals still intact and clock cap leaking everywhere  just starting cleaning when i noticed both had the same issue, the two screws on the hard drive caddy that screw the hd to the caddy have unscrewed with vibrations from the drive I would guess as they are both the same side right looking at the front of the xbox,( if the hd spun up the other way probably be the other two) and ended up in the power supply.

May be worth a drop of lock tight or a shake proof washer for anybody still using one.

 

the screw is nestled in between the the heat sinks next to the transformer. 

 

Ted

[1.6 Dead As a Door Nail.]

Yeah I guessed that, was just pumped i got it to boot at all, Stuck evox m8 1.6 on there, edited with evtool. chucked my HD from another xbox to test. 

All good so far.

Cleaned up old flux and renewed thermal pasted on gpu and cpu.

thanks for the help

Ted

[1.6 Dead As a Door Nail.]

Had sime free time tonight, so pulled this old board down and  made some progress, re flowed the mcpx. We now boot to flubber. It hangs in flubber with evo m8 1.6. Nut made some progress, it's not dead. 

 

Not got a dvd drive handy so with chip removed give error 12.

 

Might help anybody else who is struggling.

 

Ted 

 

[1.6 Dead As a Door Nail.]

Aladdin chip arrived soldered inn and lpc rebuilt.  

 

No change still dead.

 

Ted

[1.6 Dead As a Door Nail.]

Yes getting 2.3 volts on the clock cap with the mother board disconnected so that's good too.

I'll likey build a mod chip or buy one and give that a try.

 

Thanks all.

Ted

[1.6 Dead As a Door Nail.]

I've been doing some googling, this is quite a common problem on the 1.6s according to the amount of people who have posted with this issue.

 

Could it be a bios issue, corrupt or missing after a long period off no power ?

I suppose the way to test it would be with a mod chip, but its been so long since i used to mod these, is there one that actually take the place of the bios ?

 

Ted

[1.6 Dead As a Door Nail.]

collector is 3.45

emitter 5.35

base 4.6

power on is the white one,

0v when standy by,

3.4v when pressed but does fluctuate when held some times as low as 2.6 when fluctuating.

 

[1.6 Dead As a Door Nail.]

On 8/4/2019 at 5:11 PM, KaosEngineer said:

The clock cap is a 1F super cap rated at 2.5Vdc.  Brand: nichicon 

The 12Vdc line from the Power Supply Unit  (PSU) reads 0.34Vdc or 12 - 0.34Vdc ~= 11.66Vdc.

With no load attached to the 12Vdc line, the PSU's protection circuitry may automatically switch that supply level off - thus the 0Vdc reading when only the multimeter is connected to it.

You measure 5Vdc at the standby pin on the motherboard's power connector.

I think this graphic is in error for the Blue wire (PowOK) in STB (standby) mode. It should read 0Vdc, not 3.3Vdc.

The v1.6 Xbox uses 5Vdc for the standby supply level, unlike all the previous vesion PSUs which use 3.3Vdc.

 

The blue on mine 3.3 at standby

orange 5 at standby

and 0.46 on yellow at standby

 

Swapped out the power supply for another 1.6 and still no boot.

[1.6 Dead As a Door Nail.]

new one fitted (MMBT4403LT1G) still no power light or frag, whats the next component to test/replace.

Thank you.

 

TEd

[1.6 Dead As a Door Nail.]

I'll order some more. Thanks for that.

[1.6 Dead As a Door Nail.]

Thanks for the reply, it's the first one you said 3906lt1g I have ordered. I'll have a look to see if I can make out any numbers.

 

It said 2tz on the top.

Thanks

 

[1.6 Dead As a Door Nail.]

Hi, I have a 1.6 crystal, I'm the first to open it up, it has no life when the buttons are pressed, so far I have,

Tested the power supply, and the power when the power button is pressed and held. I'm getting all the correct voltage when standby and when the power button is held, it tells me the power supply is doing its thing.

The only one that is slightly out is the 12 line at stand by it shows about 0.34, when plugged on to the board but 0 when removed and just the plug probed.

It had the 5 capacitors all leaking and bulging around the power socket, so I incorrectly thought that would be the problem and changed those for some panasonic units.

Again this didn't sort the problem.

I checked the transistor at Q7C2 and was getting 3.36 volts on the collector, but to prove a point I removed it from the circuit and put it on the tester independently  it showed as a working pnp transistor. (I have ordered some new ones as it off the board so might as well replace it.)

I have read that the clock cap can be replaced with a capacitor but now cant find the correct value, as a fault clock cap can prevent power up?? plus it looks like i may have damaged this one with the heat gun, could just be the outer paint coating scorcher on closer examination though, been unplugged a while and still showing 1.66 volts.

The traces from the power/eject socket are good going up to the xyololops chip. cant see any corrosion on the underside of the board either.

so that's where I am with it at the moment any suggestions on what to test next.

I have a 1.4 board and ps that i can fit into this lovely case but would like to try and fix this one first.

The board dosen't look dead flush where the cpu sit on it slight warpage of the board with the weight of the heat sink pushing down, this may be normal though.

Thanks

Ted

[Hello Everyone.]

Hi, A little bit about me, I'm what id describe as a  mid 40s tinkerer, I like to understand and fix broken things,  I've had an infinity with the xbox for many years, was a mod/ product tester on xecuter forums for many years, until my twins were born and my priorities changed.

I have slowly gotten back into retro consoles and computers again and have gotten stuck on a 1.6 board that seems completely dead.

I'm hoping with your advice i can get it going again.

I struggle with my dyslexia, so please don't be the grammar or word police 

Thanks

Ted