HP 2113e Battery resistor

Glen Slick glen.slick at gmail.com
Sat Jun 20 22:43:13 CDT 2015

I have only looked at the "B" version of the power supply as that is
what I have in my 2117F. (Now that I think of it I'm not sure what
version of the power supply I have in my 2113B). The details for that
are covered in the 5061-1356 section of the 92851-90001_Jun79_9.pdf
manual referenced below starting on page 84 of the PDF.

As described in section 3-9 on page 105 of the PDF the Power Fail
Recovery System (PFRS) option consists of the Battery Charger Board
(A3A3) and the Battery Backup Board (A3A4) which are mounted
internally in the power supply, and the external mounted
Battery/Status Assembly. If the PFRS option is not present the Jumper
Board (A3A4) is installed internally in the power supply instead of
the Battery Charger Board (A3A3) and the Battery Backup Board (A3A4).
If you open up your system far enough to remove the lid on the power
supply you can visually inspect the installed boards to determine
whether or not the PFRS option is installed in the power supply.

The battery pack over-temperature thermistor is integrated into the
battery pack. It ends up being connected to the TEMP1 and TEMP2
signals shown on the Battery Charger Board (A3A3) schematic Sheet 6 on
page 136 of the PDF. If the PFRS option is not installed the Battery
Charger Board (A3A3) is not present and there is nothing that would
connect to the battery pack thermistor so it is not necessary for the
operation of the power supply.

If the PFRS option is installed but the thermistor or resistor
equivalent is not connected the CPU will power on but will not be
functional. I think all of the front panel lights turn on and none of
the switches have any effect. It's been a long time since I looked at
that in detail to figure out what was going on. I think some of the
voltages are at the correct level, but maybe the memory voltages are
not, and some of the power supply status signals (PSU?, PON?) indicate
the power supply is not ready and that holds the system in the
inactive state.


On Sat, Jun 20, 2015 at 7:30 PM, Marc Verdiell <marc.verdiell at gmail.com> wrote:
> Ah thanks, this is what these are for, thermistors. They are supposed to
> monitor the temperature somewhere I suppose? Attached to the batteries? The
> power supplies? The computer won't start without these I understand? Sorry I
> am a bit of a newbee with HP 1000's. Have not tried to power mine quite yet.
> Marc
>>Glen Slick <glen.slick at gmail.com> said
>>The Temperature Sense Thermistor RT1, normaly 815 ohms, is wired
>>across the two outside pins of the middle row, pins 4 and 6.
> df
>>Description page 111
>>Schematic page 168

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