T21 brief flash of HDD lamp when powering on

[solidpro]

Hi All

I've got a T21 I'm going to try and restore. Initial issue is a new one on me. When you plug it in the battery lamp comes on orange as expected.

When you press the power button the battery light goes out, the HDD flashes for about 1/10th of a second and then the battery light comes back on again. Nothing else happens - no life.

Has anyone seen this before, or know the cause?

Thanks!

[solidpro]

Ok I worked out this is known as BOD. I've ordered some of these https://www.ebay.co.uk/itm/153217409983 because it seems that either a 2k resistor or a new chip would be in order....

My question is, should I also try the 2kohm resistor between pins 24 and 16 instead of replacing the chip, or just wait and replace the whole chip?

[dr_st]

Good luck.

I had tried the 2kohm trick on an A21m that succumbed to the same issue, with zero effect. Gave the laptop away before I could try the chip replacement. Your mileage may vary...

[solidpro]

Hi

When I encounter a problem like this, I generally come back to the same question - even if I fix one, will they ALL go that way in time, or is it something that either happens/doesn't happen OR is it to do with usage....

I was trying to put together a set of good T2x machines but having fixed an 0175 issue using the parellel shorting fix, I wonder if that machine will come back out in 2 years time and have BOD!

One last thing, are the T3x/T4x machines likely to experience the same issue?

Thanks

[RealBlackStuff]

Some T30 suffer from poor soldering of one of its RAM slots.
Some T4x suffer from poor soldering of their graphics chips and the big Intel chip (Southbridge) under the wifi-card.
IMHO both can be blamed on the introduction of RoHS, specifically its use of lead-free solder.

PS: if you are interested, I may have a nice T23 for you.
1.2GHz CPU, 2x512MB RAM, wifi, new 160GB Samsung HM160HC HDD, optical drive, charger, working battery.
Perfect screen, several OSes on CD.
This T23 comes with this magnifico lid.
Price to be discussed.

[solidpro]

Soldering I can deal with. I guess I draw a line at the issues with T4x graphics (having given up on a few)....

I hate issues that aren't definitively solvable though...which is what this BOD for T2x/A20m issue feels like....

thanks

[solidpro]

Some T30 suffer from poor soldering of one of its RAM slots.

In another thread someone disputes this is ever a problem with T30's. I'm trying to find evidence of anyone actually tackling this issue and resolving it. Is it a problem?

Thanks

[RealBlackStuff]

viewtopic.php?f=28&t=73443&hilit=repair+t30+ram+slot

[solidpro]

Thanks. Just trying to establish if this reflow method can be done without disassembling the machine (I don't know if some pins are on the reverse of the board seen within the memory bay....

[SMA]

The memory sockets are surface mounted.
That is: No pins on the reverse side of the board.

[Gonzaleitor]

Ok I worked out this is known as BOD. I've ordered some of these https://www.ebay.co.uk/itm/153217409983 because it seems that either a 2k resistor or a new chip would be in order....

My question is, should I also try the 2kohm resistor between pins 24 and 16 instead of replacing the chip, or just wait and replace the whole chip?

Sorry to necro this. But did you try the resistance soldering to the ADP 3421 chip?

[Gonzaleitor]

Sorry to necro this. But did you try the resistance soldering to the ADP 3421 chip?

I soldered the 2.2 kOhm resistor to the adp3421 chip and now the laptop works. Only need a compatible TN panel.

[solidpro]

Any pics of exactly what you did? I tried the resistor method and it did absolutely nothing.

[Gonzaleitor]

Any pics of exactly what you did? I tried the resistor method and it did absolutely nothing.

No problem, i'll upload a pic in 2 or 3 hours when i get home. You have to be careful not to bridge the pins.

[solidpro]

And Time
Goes By
So Slowly
I've hungered for...
your pics.

[Gonzaleitor]

And Time
Goes By
So Slowly
I've hungered for...
your pics.

Sorry for the delay, solidpro. My IP must be blocked or something like that, i discovered today that I can connect to the forum through a VPN

It's not that tidy, but it worked.