Help identify this IC

[Bicurico]

Hi,

Can someone help me out and tell me what these orange/yellow IC's are?

How can I test if they are OK?

The picture is of one of my HP 8594E. This device stopped working suddenly (was turned on). No smoke or explotion. The motherboard shows now sign of any broken component. If I turn the device on, the CRT goes on but shows no picture and the device seems dead - no clicking of the relais, just the CRT, power LED and fans.

This picture shows where the PSU attaches (connector on the other side of the board, you can see the J1 pins). I imagine that the fault could be these yellow IC's - are the some kind of fuse?

Thanks,
Vitor

[Lee Leduc]

Looks like a resistor network. Most likely used as termination for the ribbon cable.

https://www.lintechcomponents.com/product/014135829/18100301/1LQK8

[ArthurDent]

Lee Leduc is correct. The maker's symbol indicates it was made by Bourns in 1994.

[Bicurico]

Thanks!

How could I measure them to see if they are the reason the device doesn't power up?

I can't find any datasheet...

Regards,
Vitor

[helius]

Those resistor networks are terminating a data bus from the mainframe's motherboard (note the silkscreen for the connector says "MTHRBD"). They have been labeled with internal HP part numbers. The component list states:

Code: [Select]

U401        1810-0301          1            NET-RES 8 51.0 OHM 16-DIP

Which means, a resistor network of 8 resistors, each 51 ohms, in a DIP-16 package.
The Bourns part number is 4116R-1-510.
Datasheet.

[ArthurDent]

I doubt very much that the resistor networks are your problem. The 51.0 ohms value helius found for the part is also coded on the top of the network (510). If there are 8 resistors and the network has 16 pins, they probably are wired 1-16, 2-15, etc and if you unplug the cable you can verify this with an ohmmeter. 

[Bicurico]

Thank you guys!

That was a great help. I will measure the pins ASAP and check those IC's out.

I doubt anything much dramatic happend, otherwise there would be some burned/exploded component.

On the other hand, not having any sign on the motherboard makes it difficult to "see" what could have happend, so I will work my way from power inlet.

Regards,
Vitor