Fitting to the page number, todays star is the EG&G / PAR / Ametek
Model 5113 Low-Noise Preamplifier![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1551025)
After
the incident the two input dual-gate FET 2N5564 were replaced with parts from
Linear Systems and it would amplify small signal AC again - but the overload light was still always lit. Recently a fresh look revealed an huge DC offset and the AD744 opamp as it's likely source.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1551037)
Today, (how nice!) the replacement arrived and was promptly soldered in place. To my delight, the overload light turned offf! I will have to take a closer look at it to check, if it truly is "like a bought one" now, but I'll sleep good tonight nonetheless
![Azn ^-^](https://www.eevblog.com/forum/Smileys/default/azn.gif)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1551031)
Over the PCB sits a small shield (look closely, it complains!) and a full size metal tray with two flat 12v lead acid batterys for floating use.
Edit: Now to check, if I can find all the case parts again
![Laughing :-DD](https://www.eevblog.com/forum/Smileys/default/smiley_laughing.gif)