Notebook 4820TG not starting

Gunnar45

The unit is not charging and there are no indication LED's showing when connected to the charger.

It is also not functioning with the battery removed.

 

Checked the charger with a digital multimeter, output 19.5V.

But with the charger connected, and battery taken out, there is no voltage on any of the contacts of the battery connectors. (Measured between all of them)

 

Resistance measured from DCin jack to the two larger contacts of the battery connection:

Minus on DCin jack to any of the two larger contact shows a few ohms.

Plus on DC in jack to any of the two larger contacts shows around 1Mohm, decreasing with time on the second contact.

 

Any suggestion on what to do?

I have the 4820 service manual, but must I really almost have to completely disassemble the unit to get at the porwer supply circuit?

Does anyone have a sketch of how the powersupply is wired from DCin jack to battery?

And the function/designation of the eight battery connection contacts (two large and six smaller)

 

Any suggstions?

- Charger not capable of providing power, only voltage?

- Bad contact in the DCin jack connection? (I cleaned all contacts with CRC)

- Interruption in the internal power circuit? (Are there any components or fuses  inbetween battery connectors and DCin jack which can fail?)

- Any other ideas?

 

The unit worked fine last time I used it but I haven't used it for around two months before I discovered this problem.

 

Looking forward to some help on this,

Gunnar45

Gunnar45

Update on the previous, I disassembled the machine with help of the service guide 4820T.

It went fine even though there were some differences between the guide and my unit.

 

Anyway, I could confirm that the connection from the DC-jack to the power connector link of the main board is OK with 19.5V measured on the board side of the connector.

But only the negative can be measured at the battery connector. (On the rightmost connector blade when seen from the front)

There are a total of eight connector blades which plug into the battery. The two rightmost of them are slightly larger in size than the other six. As said, the rightmost blade seems to be the negative pole, but which one is the positive??

On the battery there is a plus-sign on the left side of its female connector.

Shouldn't it be possible to measure the 19.5V supply voltage on the battery power connector of the MB when power is connected to it?

 

So, again, I guess I would need to know how the positive is routed, points where to measure it, etc.

 

Any advice is appreciated!

Gunnar45