# DIAG: Detect digitizer issues by drawing a grid

## Overview

Drawing a regular grid on your tablet can help diagnose certain kinds of problems such as 

* Digitizer failure. See [TSG: Pen skipping vertical or horizontal bands](/drawtab/troubleshoot/tsg-skipping-bands.md) - where regions of the tablet simply do not detect the pen
* [Electromagnetic interference](/drawtab/guides/general/electromagnetic-interference.md) where things like magnets distort straight lines     

## The Grid to draw

How many lines do you need on the grid? The example below shows you roughly the grid to draw

<figure><img src="/files/QOkVTAMpDCn8GMjKOEJJ" alt=""><figcaption></figcaption></figure>

The example below might also be enough

<figure><img src="/files/J15eO7HFdfUxJd89XalL" alt=""><figcaption></figcaption></figure>

But this example below is definitely not enough

<figure><img src="/files/2cezaVsoT2IF6tUWAgPk" alt=""><figcaption></figcaption></figure>

Try to draw them with a ruler or just try to draw them straight enough with your hand. It's important that your lines aren't too "wobbly" otherwise they will interfere with the dignosis of problems.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.sevenpens.com/drawtab/troubleshoot/diag-draw-grid.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.